[ovs-dev] [PATCH v7 2/2] netdev-afxdp: NUMA-aware memory allocation for XSK related memory

Eelco Chaudron echaudro at redhat.com
Wed Dec 18 08:24:28 UTC 2019



On 17 Dec 2019, at 23:27, Yi-Hung Wei wrote:

> Currently, the AF_XDP socket (XSK) related memory are allocated by 
> main
> thread in the main thread's NUMA domain.  With the patch that detects
> netdev-linux's NUMA node id, the PMD thread of AF_XDP port will be run 
> on
> the AF_XDP netdev's NUMA domain.  If the net device's NUMA domain
> is different from the main thread's NUMA domain, we will have two
> cross-NUMA memory accesses (netdev <-> memory, memory <-> CPU).
>
> This patch addresses the aforementioned issue by allocating
> the memory in the net device's NUMA domain.

Did not try the patch yet, but it looks good. One quick comment below…

> Signed-off-by: Yi-Hung Wei <yihung.wei at gmail.com>
> ---
>  Documentation/intro/install/afxdp.rst |  2 +-
>  acinclude.m4                          |  5 ++++-
>  include/sparse/automake.mk            |  1 +
>  include/sparse/numa.h                 | 27 
> +++++++++++++++++++++++++++
>  lib/netdev-afxdp.c                    | 21 ++++++++++++++++++---
>  5 files changed, 51 insertions(+), 5 deletions(-)
>  create mode 100644 include/sparse/numa.h
>
> diff --git a/Documentation/intro/install/afxdp.rst 
> b/Documentation/intro/install/afxdp.rst
> index 7b0736c96114..c4685fa7ebac 100644
> --- a/Documentation/intro/install/afxdp.rst
> +++ b/Documentation/intro/install/afxdp.rst
> @@ -164,7 +164,7 @@ If a test case fails, check the log at::
>
>  Setup AF_XDP netdev
>  -------------------
> -Before running OVS with AF_XDP, make sure the libbpf and libelf are
> +Before running OVS with AF_XDP, make sure the libbpf, libelf, and 
> libnuma are
>  set-up right::
>
>    ldd vswitchd/ovs-vswitchd
> diff --git a/acinclude.m4 b/acinclude.m4
> index 542637ac8cb8..73ed11d701aa 100644
> --- a/acinclude.m4
> +++ b/acinclude.m4
> @@ -286,9 +286,12 @@ AC_DEFUN([OVS_CHECK_LINUX_AF_XDP], [
>      AC_CHECK_FUNCS([pthread_spin_lock], [],
>        [AC_MSG_ERROR([unable to find pthread_spin_lock for AF_XDP 
> support])])
>
> +    AC_CHECK_LIB(numa, numa_alloc_onnode, [],
> +      [AC_MSG_ERROR([unable to find libnuma for AF_XDP support])])
> +
>      AC_DEFINE([HAVE_AF_XDP], [1],
>                [Define to 1 if AF_XDP support is available and 
> enabled.])
> -    LIBBPF_LDADD=" -lbpf -lelf"
> +    LIBBPF_LDADD=" -lbpf -lelf -lnuma"
>      AC_SUBST([LIBBPF_LDADD])
>
>      AC_CHECK_DECL([xsk_ring_prod__needs_wakeup], [
> diff --git a/include/sparse/automake.mk b/include/sparse/automake.mk
> index 073631e8c082..974ad3fe55f7 100644
> --- a/include/sparse/automake.mk
> +++ b/include/sparse/automake.mk
> @@ -5,6 +5,7 @@ noinst_HEADERS += \
>          include/sparse/bits/floatn.h \
>          include/sparse/assert.h \
>          include/sparse/math.h \
> +        include/sparse/numa.h \
>          include/sparse/netinet/in.h \
>          include/sparse/netinet/ip6.h \
>          include/sparse/netpacket/packet.h \
> diff --git a/include/sparse/numa.h b/include/sparse/numa.h
> new file mode 100644
> index 000000000000..3691a0eaf729
> --- /dev/null
> +++ b/include/sparse/numa.h
> @@ -0,0 +1,27 @@
> +/*
> + * Copyright (c) 2019 Nicira, Inc.
> + *
> + * Licensed under the Apache License, Version 2.0 (the "License");
> + * you may not use this file except in compliance with the License.
> + * You may obtain a copy of the License at:
> + *
> + *     http://www.apache.org/licenses/LICENSE-2.0
> + *
> + * Unless required by applicable law or agreed to in writing, 
> software
> + * distributed under the License is distributed on an "AS IS" BASIS,
> + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or 
> implied.
> + * See the License for the specific language governing permissions 
> and
> + * limitations under the License.
> + */
> +
> +#ifndef __CHECKER__
> +#error "Use this header only with sparse.  It is not a correct 
> implementation."
> +#endif
> +
> +/* Avoid sparse warning: non-ANSI function declaration of function" 
> */
> +#define numa_get_membind_compat() numa_get_membind_compat(void)
> +#define numa_get_interleave_mask_compat() 
> numa_get_interleave_mask_compat(void)
> +#define numa_get_run_node_mask_compat() 
> numa_get_run_node_mask_compat(void)
> +
> +/* Get actual <numa.h> definitions for us to annotate and build on. 
> */
> +#include_next<numa.h>
> diff --git a/lib/netdev-afxdp.c b/lib/netdev-afxdp.c
> index 4c1f9c68270a..2d6f739b4b67 100644
> --- a/lib/netdev-afxdp.c
> +++ b/lib/netdev-afxdp.c
> @@ -26,6 +26,7 @@
>  #include <linux/rtnetlink.h>
>  #include <linux/if_xdp.h>
>  #include <net/if.h>
> +#include <numa.h>
>  #include <poll.h>
>  #include <stdlib.h>
>  #include <sys/resource.h>
> @@ -469,7 +470,7 @@ xsk_configure_all(struct netdev *netdev)
>  {
>      struct netdev_linux *dev = netdev_linux_cast(netdev);
>      int i, ifindex, n_rxq, n_txq;
> -    int qid = 0;
> +    int qid = 0, err = 0;
>
>      ifindex = linux_get_ifindex(netdev_get_name(netdev));
>
> @@ -477,6 +478,14 @@ xsk_configure_all(struct netdev *netdev)
>      ovs_assert(dev->tx_locks == NULL);
>
>      n_rxq = netdev_n_rxq(netdev);
> +
> +    /* Allocate all the xsk related memory in the netdev's NUMA 
> domain. */
> +    struct bitmask *old_bm = numa_get_membind();
> +    struct bitmask *new_bm = numa_allocate_nodemask();
> +    netdev_get_numa_id(netdev);
> +    numa_bitmask_setbit(new_bm, dev->numa_id);

Rather than access the device specific structure, why not use the return 
value?

numa_bitmask_setbit(new_bm, netdev_get_numa_id(netdev));

> +    numa_set_membind(new_bm);
> +
>      dev->xsks = xcalloc(n_rxq, sizeof *dev->xsks);
>
>      if (dev->xdp_mode == OVS_AF_XDP_MODE_BEST_EFFORT) {
> @@ -518,11 +527,17 @@ xsk_configure_all(struct netdev *netdev)
>          ovs_spin_init(&dev->tx_locks[i]);
>      }
>
> -    return 0;
> +    goto out;
>
>  err:
>      xsk_destroy_all(netdev);
> -    return EINVAL;
> +    err = EINVAL;
> +
> +out:
> +    numa_set_membind(old_bm);
> +    numa_bitmask_free(old_bm);
> +    numa_bitmask_free(new_bm);
> +    return err;
>  }
>
>  static void
> -- 
> 2.17.1



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